Texas Cosmetology Operator Written ExamAnatomy and PhysiologyHard
A cosmetologist is discussing hair growth with a client. Which of the following cells is primarily responsible for producing the keratin that forms the hair shaft?
- ALangerhans cells
- BKeratinocytes
- CMelanocytes
- DFibroblasts
Show answer & explanationAnswer & explanation
Correct answer: B. Keratinocytes
Keratinocytes are the predominant cells in the epidermis and hair follicles. Their primary function is to produce keratin, a structural protein that forms the hair shaft, skin, and nails.
Why the other options are wrong
- A. Langerhans cells are immune cells found in the epidermis, involved in immune responses.
- C. Melanocytes produce melanin, which determines hair and skin color, but not the structural keratin.
- D. Fibroblasts produce collagen and elastin, primarily found in the dermis, contributing to skin structure but not directly forming the hair shaft.
Keratinocytes
Keratinocytes are the most abundant cells in the epidermis and hair follicles, responsible for producing keratin.
- Form the protective barrier of the skin.
- Continuously divide and move upwards, eventually forming the stratum corneum.
- Synthesize keratin, a tough, fibrous protein.
- Crucial for the structure of hair and nails.
Memory trick: Keratinocytes 'create' keratin.